Conditions InDepth: Gallstones

Gallstones form when cholesterol or bile, which is stored in the gallbladder, hardens into pieces of stone-like material. Gallstones are made of about 75% cholesterol salts. The remaining 25% is made up of bilirubin salts, a bile pigment and calcium carbonate. Gallstones can be as small as a grain of sand or as large as a golf ball. The gallbladder can develop just one large stone, hundreds of tiny stones, or almost any combination.

Gallstones can block the normal flow of bile if they lodge in any of the ducts that carry bile from the liver to the small intestine. Bile trapped in these ducts can cause inflammation in the gallbladder, the ducts, or, rarely, the liver.

Gallstones can cause several related problems including:

Gallstone pancreatitis—A gallstone blocks the opening to the pancreatic duct, and digestive enzymes become trapped in the pancreas causing extremely painful inflammation

Biliary colic—Pain caused by a gallstone stuck in the bile duct, a tube that carries bile to the small intestine

Cholecystitis—A stone caught in the bile duct causing inflammation of the gallbladder

Cholangitis—An infection of the bile ducts

Gallstone ileus—The gallbladder attaches to the small intestine, creating an abnormal opening through which the stone can travel and cause an obstruction of the small bowel

Gallstones are a common medical problem. About 10% to 15% of the adult population of the United States has gallstones. However, about 80% of people who have gallstones have no symptoms. This condition is referred to as silent gallstones and usually does not require treatment.

Revision Information

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.